answer to a question on ruby-talk

filter.rb

#regexes for find/replace
add_tabs = /^(term1)/
remove_tab = /\t(\tterm2)/
clear_stuff = /.*hat\.goat\sthis thing\sthat thing\sstuff\scheese/m


#read file and replace
puts "Paste in your input:"
while (line = gets)
  next if $. == 1 .. line =~ clear_stuff
  print line.gsub(add_tabs, "\t\t\\1").gsub(remove_tab, "\\1")
end